If you want to add the Login With Facebook button to an article, or anywhere else on your site, easily, simply use the {JFBCLogin} tag. It will be replaced when displayed with the Login With Facebook button. There's additional parameters you can use to customize the functionality a little, which you can see toward the bottom of this page of the config guide:
www.sourcecoast.com/jfbconnect/docs/conf...ation-guide?start=13
As for the pop-up, there's not much we can do about that. There's a few changes we're planning for the next point release (3.2.2) which may help fix any pop-up problems you see, but I can't guarantee it will. That pop-up is completely controlled by Facebook, and they are continually improving compatibility issues like that, which has been brought up to them many times. Most user's don't see the pop-up remain, but it does happen under a variety of browser, OS, and other factors.
Thanks,
Alex